clouformation

change sets

tf plan → create changesets tf apply - > direct update or use change sets and apply them

Rollback behavior

In case of provisioning failure you can either

• choose to keep successfully created resources
• rollback all of the resources
  • you can use deletion policy or
  • you can simply delete all of the resources

Deletion policy

Resources:
  MyVolume:
    Type: AWS::EC2::Volume
    DeletionPolicy: Retain
    Properties:
      Size: 10
      AvailabilityZone: us-east-1a

Supported Values:

1. Retain
   → Resource stays. You must manually delete it later.
2. Snapshot
   → For snapshot-able resources (e.g., RDS, EBS)
   → Automatically creates a snapshot before deletion.
3. Delete (default)
   → Resource is deleted when stack is deleted or rolled back.

Important:

• DeletionPolicy is per-resource.
• Doesn’t protect from explicit deletes outside CloudFormation.
• Doesn’t stop updates that replace the resource.

Termination protection

• If you attempt to delete a stack with termination protection enabled, the deletion fails and the stack - including its status - remains unchanged